February 15, 2018

Soybean Harvest Slowed in Mato Grosso due to Wet Weather

Author: Michael Cordonnier/Soybean & Corn Advisor, Inc.

Heavy rains in north-central Mato Grosso have resulted in localized harvest loses for Brazilian soybean producers. The weather had been good during the growing season and farmers were expecting yields similar to last year in the range of 55 sacks per hectare (50.8 bu/ac), but two weeks of constant rain has frustrated their efforts to harvest their soybeans.

The problem seems to be worse north of the city of Sinop in north-central Mato Grosso. Heavy rains over this past weekend have flooded fields and kept the combines parked. Farmers that have been able to harvest are reporting poor seed quality with high seed moisture (some as high as 40%), moldy and shriveled soybeans and even some soybeans sprouting in the pods.

These problems are localized in Mato Grosso. In areas not impacted by the heavy rains, farmers are reporting soybean yields above 60 sacks per hectare (52.2 bu/ac). Fortunately the forecast for northern Mato Grosso is calling for lighter and more scattered rains, at least in the near term.

In order to speed up the harvest, many farmers in Mato Grosso apply a desiccant to the soybeans once the crop approaches physiological maturity. The desiccant is applied when the crop has reached the R7 stage, which is when a good portion of the leaves have started to turn yellow. At the R7 stage, the seeds have reached their maximum weight and the plant no longer is translocating nutrients to the seeds. From that point forward, the seeds only lose water.

Once a desiccant is applied, the leaves drop off and the stems dry out. The desiccant makes the crop more uniform, it eliminates weeds, and the crop could be ready for harvesting in a few as five days. If a desiccant is applied before the plant matures, there could be potential yield losses. Farmers must pay close attention to the weather forecast before they apply a desiccant because it should only be applied when the forecast is calling for dryer weather.

The reason why farmers in Mato Grosso would apply a desiccant is to allow enough time to plant a second crop of corn. The safrinha corn must be planted as early as possible so that the corn makes it through the grain filling period before the onset of the dry season.